4.4-stable patches

added patches:
	alsa-pcm-avoid-possible-info-leaks-from-pcm-stream-buffers.patch

diff --git a/queue-4.4/alsa-pcm-avoid-possible-info-leaks-from-pcm-stream-buffers.patch b/queue-4.4/alsa-pcm-avoid-possible-info-leaks-from-pcm-stream-buffers.patch
new file mode 100644 (file)
index 0000000..7a5f081
--- /dev/null
+++ b/queue-4.4/alsa-pcm-avoid-possible-info-leaks-from-pcm-stream-buffers.patch
@@ -0,0 +1,43 @@
+From add9d56d7b3781532208afbff5509d7382fb6efe Mon Sep 17 00:00:00 2001
+From: Takashi Iwai <tiwai@suse.de>
+Date: Wed, 11 Dec 2019 16:57:42 +0100
+Subject: ALSA: pcm: Avoid possible info leaks from PCM stream buffers
+
+From: Takashi Iwai <tiwai@suse.de>
+
+commit add9d56d7b3781532208afbff5509d7382fb6efe upstream.
+
+The current PCM code doesn't initialize explicitly the buffers
+allocated for PCM streams, hence it might leak some uninitialized
+kernel data or previous stream contents by mmapping or reading the
+buffer before actually starting the stream.
+
+Since this is a common problem, this patch simply adds the clearance
+of the buffer data at hw_params callback.  Although this does only
+zero-clear no matter which format is used, which doesn't mean the
+silence for some formats, but it should be OK because the intention is
+just to clear the previous data on the buffer.
+
+Reported-by: Lionel Koenig <lionel.koenig@gmail.com>
+Cc: <stable@vger.kernel.org>
+Link: https://lore.kernel.org/r/20191211155742.3213-1-tiwai@suse.de
+Signed-off-by: Takashi Iwai <tiwai@suse.de>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ sound/core/pcm_native.c |    4 ++++
+ 1 file changed, 4 insertions(+)
+
+--- a/sound/core/pcm_native.c
++++ b/sound/core/pcm_native.c
+@@ -587,6 +587,10 @@ static int snd_pcm_hw_params(struct snd_
+       while (runtime->boundary * 2 <= LONG_MAX - runtime->buffer_size)
+               runtime->boundary *= 2;
+ 
++      /* clear the buffer for avoiding possible kernel info leaks */
++      if (runtime->dma_area)
++              memset(runtime->dma_area, 0, runtime->dma_bytes);
++
+       snd_pcm_timer_resolution_change(substream);
+       snd_pcm_set_state(substream, SNDRV_PCM_STATE_SETUP);
+ 

diff --git a/queue-4.4/series b/queue-4.4/series
index 6447f58f7ce1b3c9b48eb6df012acedd7d989496..732304dee49af8fcfda7861e4129b52441ab5912 100644 (file)
--- a/queue-4.4/series
+++ b/queue-4.4/series
@@ -71,3 +71,4 @@ btrfs-do-not-call-synchronize_srcu-in-inode_tree_del.patch
 btrfs-return-error-pointer-from-alloc_test_extent_bu.patch
 btrfs-abort-transaction-after-failed-inode-updates-i.patch
 btrfs-fix-removal-logic-of-the-tree-mod-log-that-lea.patch
+alsa-pcm-avoid-possible-info-leaks-from-pcm-stream-buffers.patch